As illustrated in FIG. 21, one of the “activation control devices for at least one occupant protection device” known hitherto (hereinafter also referred to as “prior-art device”) includes a floor sensor FL on a floor of a cabin of a vehicle. Further, the prior-art device includes a left satellite sensor FrL and a right satellite sensor FrR respectively at a front left side portion and a front right side portion of the vehicle.
Those sensors are configured to detect an acceleration in a vehicle front-rear direction applied to the vehicle. The prior-art device is configured to identify a collision form (that is, identify which of head-on collision, oblique collision, offset collision, pole collision and the like the collision form is) of the vehicle based on the detection values of those sensors, and to activate the occupant protection devices based on the identification result (for example, refer to Japanese Patent Application Laid-open No. 2001-30873).